National Weather Service Raw Text Product

055 
NOUS43 KLOT 132036
PNSLOT
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-141200-

Public Information Statement
National Weather Service Chicago IL
236 PM CST Fri Nov 13 2020 /336 PM EST Fri Nov 13 2020/

...NWS DAMAGE ASSESSMENT FOR THE 11/10/2020 SEVERE WEATHER EVENT…

.OVERVIEW...
On November 10, 2020, a line of severe thunderstorms moved 
through northern Illinois and northwest Indiana with damaging 
winds in excess of 60 mph. Embedded in the line were several 
pockets of winds estimated between 70 and 85 mph that brought
significant damage. Numerous trees and farm buildings were 
damaged near Mount Morris, IL, in and around Winnebago and 
Rockford, IL, and across northern Boone and McHenry counties in 
Illinois near the Wisconsin state line. Additionally, at least two
brief EF-0 tornadoes with peak winds of 80 mph were produced by 
the line, the first in rural DeKalb County, IL and the second near
Lily Lake, IL. Finally, the line of thunderstorms produced hail 
larger than one inch in diameter in and around the Rockford area.


.MOUNT MORRIS TO WINNEBAGO STRAIGHT-LINE WINDS...

Estimated peak wind:    85 mph
Fatalities:             0
Injuries:               0

Start date:             11/10/2020
Start time:             3:15 PM CST
Start location:         2 SW Mount Morris

End date:               11/10/2020
End time:               3:40 PM CST
End location:           6 NNE Winnebago

Strong straight-line winds of 70 to 85 mph occurred in a corridor
stretching roughly from Mount Morris to just northwest of 
Rockford. The swath of wind damage started southwest of Mount 
Morris, where dozens of trees were damaged or downed and a photo 
showed a large chunk of wood from one tree impaled through another
tree. Further northeast in Ogle County, several trees and power 
lines were downed north of Byron. In Winnebago County, extensive 
damage occurred to trees, signs, and roofs in the village of 
Winnebago, and a grain silo and barn collapsed northeast of there,
killing two cattle. Additional wind damage was reported farther 
to the northeast, but wasn’t as significant as the damage seen 
to the southwest.


.RURAL BOONE COUNTY AND RURAL MCHENRY COUNTY STRAIGHT-LINE WINDS...

Estimated peak wind:    80 mph
Fatalities:             0
Injuries:               0

Start date:             11/10/2020
Start time:             4:00 PM CST
Start location:         4 N Capron

End date:               11/10/2020
End time:               4:04 PM CST
End location:           4 NW Harvard

Strong straight-line winds of 70 to 80 mph occurred in rural 
northern Boone County and the far northwest corner of McHenry 
County. In addition to downing several trees and power lines, 
strong winds compromised several barns and outbuildings, leading 
to their doors and/or roofs being blown off, and in a few cases, 
causing the structures to be blown off their foundations and/or 
collapse. Wind damage continued across the state line into 
Wisconsin.


.RURAL DEKALB COUNTY EF-0 TORNADO...

Rating:                 EF-0
Estimated peak wind:    80 mph
Path length /Statute/:  9.8 miles
Path width /Maximum/:   50 yards
Fatalities:             0
Injuries:               0

Start date:             11/10/2020
Start time:             4:19 PM CST
Start location:         4.5 NW Somonauk

End date:               11/10/2020
End time:               4:31 PM CST
End location:           1 E Hinckley 

Based on a radar-indicated tornado debris signature and 
information provided by DeKalb County emergency management 
officials, an EF-0 tornado with peak winds of 80 mph, path length 
of around 10 miles, and max width of 50 yards touched down near 
Route 23 northwest of the town of Somonauk and traveled northeast 
mainly through farm fields. A grain silo was damaged near the 
intersection of Somonauk and Bastian roads, and damage to trees 
and powerlines was observed along the path of the tornado. The 
tornado appeared to end near Route 30 just southeast of Hinckley.
It is possible that the tornado continued northeast toward 
Kaneville where additional downed power lines were reported, but a
lack of a more robust radar signature and additional damage 
reports precluded an extension of the tornado path northeastward 
or the addition of a second tornado altogether.



.LILY LAKE EF-0 Tornado...

Rating:                 EF-0
Estimated peak wind:    80 mph
Path length /Statute/:  4 miles
Path width /Maximum/:   50 yards
Fatalities:             0
Injuries:               0

Start date:             11/10/2020
Start time:             4:39 PM CST
Start location:         3 NW Elburn

End date:               11/10/2020
End time:               4:42 PM CST
End location:           3 N Elburn

Based on information gathered on social media, from emergency 
management officials, as well as an analysis of radar data, an 
EF-0 tornado touched down near Francis Road northwest of Elburn 
and damaged nearby trees and the roof of an outbuilding. The 
tornado continued northeast and crossed Route 47 south of Route 
64, based on an eyewitness report. After crossing Route 64, the 
tornado damaged trees on Hanson Road. The tornado is thought to 
have lifted soon thereafter based on a lack of downstream reports 
of damage. Radar data was supportive of a weak tornado based on a 
compact rotational couplet and small reductions in correlation 
coefficient values (an indication of lofted small debris pieces).

EF Scale: The Enhanced Fujita Scale Classifies Tornadoes into the
following categories.

EF0...Weak......65 to 85 mph
EF1...Weak......86 to 110 mph
EF2...Strong....111 to 135 mph
EF3...Strong....136 to 165 mph
EF4...Violent...166 To 200 mph
EF5...Violent...>200 mph

NOTE:
The information in this statement is PRELIMINARY and subject to
change pending final review of the event and publication in NWS
Storm Data. 

$$

NWS Chicago